The topic came up when the TODAY hosts were discussing family traditions to mark milestones such as the first day of school, and Hager revealed hers — although it's not tied to any particular milestone.

Dog pile! Jenna Bush Hager and her family pile on top of each other. Jenna Bush Hager

"We do a family dog pile, which is so weird," she said, revealing a photo of her and her husband Henry, with their two daughters piled on their backs.

"This is the same picture I took with my parents," she added. "It has nothing to do with anything, but I have a tradition."

George W. Bush with daughters Jenna Bush Hager and Barbara Bush. The dog pile is a longtime family tradition! Jenna Bush

And now we have photographic evidence: a throwback photo of Hager and her sister Barbara Bush on their dad's back, on the grass in Washington, D.C.